/Engine/Plugins/Editor/ObjectMixer/ObjectMixer/Source/ObjectMixer/Public/Views/List/Modes/ObjectMixerOutlinerHierarchy.h
Adds all the direct and indirect children of a world to OutItems
void CreateWorldChildren ( [UWorld](API\Runtime\Engine\Engine\UWorld) * World, [TArray](API\Runtime\Core\Containers\TArray)< FSceneOutlinerTreeItemPtr > & OutItems ) const